Merge branch '6.0'

diff --cc files/lib/system/exporter/Kunena3xExporter.class.php
Simple merge

diff --cc files/lib/system/exporter/PhpBB31xExporter.class.php
Simple merge

diff --cc files/lib/system/exporter/SMF2xExporter.class.php
Simple merge

diff --cc files/lib/system/exporter/WordPress3xExporter.class.php
Simple merge